s1 = "a"+"b"+"c"
print(s1)
lst  = [1,2,3,4,5]
lst2= '1,2,3,4,5'
print(lst2.join('.'))

print([1]*50)
print([1,2000]*50)
print("str"*50)
print(lst*50)

# 比较列表中每一个元素
ls1 = [1,2,3,4,10,100]
ls2 = [2,3,4,5,6]
ls3 = [2,3,4,5,8]
print(ls1<ls3)

# in 在不在内
t1 = (1,2,3,4,5)
print(10 in t1) #false

lst1 = [1,2,3,4,5]
print(max(lst1))
print(sum(lst1))